Specifically, upregulation of apolipoprotein A1 (APOA1), APOC3, apolipoprotein E (APOE), TTR, and α2-macroglobulin (α2M) was observed in both POAG (3.5-, 6.3-, 3.6-, 2.1-, and 7.0-fold, respectively) and PEXG (2.9-, 6.5-, 3.4-, 2.3-, and 7.5-fold, respectively) groups, compared with controls, which may reflect the severity of glaucoma [98]. This evidence concerns the gene A2M and glaucoma.